data:[][;charset=][;base64],
.demoImg{ background-image: url("data:image/jpg;base64,/9j/4QMZRXhpZgAASUkqAAgAAAAL...."); }
<img width="40" height="30" src="data:image/jpg;base64,/9j/4QMZRXhpZgAASUkqAAgAAAAL...." />